Question

Fie functia f:R-R ,f(x)=2x-1.Sa se calculeze suma s=f(1)+f(2)+....+f(2018)

Answer 1

f(x)=2x-1

s=f(1)+f(2)+...+f(2018)

=2 ori 1 - 1 + 2 ori 2 -1 + ... + 2 ori 2018 - 1

= 2(1+2+...+2018) -1 ori cati termeni sunt

= 2(2018 ori 2019 : 2) -1 ori 2018

= 2018 ori 2019 - 2018

= 4074342 - 2018

= 4072324